The present invention generally relates to gaming machines and more generally relates to a door-monitoring security alert for a gaming machine.
Casino operators rely on a variety of systems for maintaining casino security. Where gaming machines, such as slot machines, poker or other card game machines, keno machines, and the like are used, the machines themselves often contain various security measures to prevent casino guests and employees from tampering with or stealing from the gaming machines, and to alert casino operators when tampering or theft may have occurred.
Gaming machines have a variety of door types, which allow access to the machine to collect coins, make repairs, perform evaluations and updates, and so forth. One type of security measure alerts casino operators or disables gaming machines when the doors of machines have been opened. Some such devices run on power from the gaming machine, and if that power is interrupted or turned off, tampering or theft may go undetected. In addition, it is possible to tamper with some existing door monitor devices by opening the door, disabling the monitor, and then closing the door. With such a device, it is possible to open the door during a routine coin collection or machine evaluation and disable the monitor so that the door can be opened later to allow theft or tampering with the machine.
Door-monitoring devices often employ switches and electronic xe2x80x9clatchesxe2x80x9d which indicate whether the switches have been activated. An electronic latch is a circuit which, having received one set of inputs, will continually give one predefined output until enacted upon by a xe2x80x9cresetxe2x80x9d set of inputs. In a door-monitoring application, for example, such a circuit will continue to show that a door has been opened or disable a machine after the door has been opened and then closed.
One type of prior art door-monitoring device 1 is shown in FIG. 1. In this prior art device, a battery 2 is electrically connected through a resistor 12 to the xe2x80x9cinverted-setxe2x80x9d or xe2x80x9cS-barxe2x80x9d input 6 of an electronic set/reset latch (xe2x80x9cS/R latchxe2x80x9d) 8. The prior art device has a connection 10 through a switch 4 to ground 14 between the resistor 12 and the S-bar input 6 of the S/R latch 8. The S/R latch 8 further contains an xe2x80x9cinverted-resetxe2x80x9d or xe2x80x9cR-barxe2x80x9d input 16 coupled to a game microprocessor 22, and a xe2x80x9cQxe2x80x9d output 20 to the game microprocessor 22. The S/R latch 8 is powered by a latch power supply 24, which may be the battery 2.
The prior art door-monitoring device 1 is designed so that the switch 4 is open when a door to be monitored is closed. When the door to be monitored is opened, the switch 4 closes, and current flows from the battery 2, through the resistor 12 and through the switch 4 to ground 14. This pulls the S-bar input 6 low, activating it. This gives an output signal at the Q output 20, informing the game microprocessor 22 that the door has been opened. This output from the Q output will continue until the door is closed and the R-bar input 16 is activated. In a normal situation where a door would be opened, such as during machine maintenance or during collection from a gaming machine, the door would be closed afterward and the reset input 16 would be activated, thereby informing the game microprocessor 22 that the door has been properly closed. The R-bar input 16 may itself be activated (i.e., given a xe2x80x9c0xe2x80x9d input) by the game microprocessor 22 as shown in FIG. 1.
The design of the prior art door-monitoring device 1 has a fault, in that if the connections 24 in the vicinity of the switch 4 are accidentally or intentionally broken at any point, the S-bar input 6 will always stay high and thus the S/R latch 8 will indicate that the door has been closed. Thus, when the R-bar input 16 is activated by the microprocessor 22 following the breaking of the connection 24, the microprocessor 22 will receive a signal indicating that the door has been properly closed, even if the door is opened and closed a number of times following the breaking of the connection 24. This design allows for a scenario wherein a gaming machine door is legitimately opened, with the connection 24 being broken while the door is opened. Once the R-bar input 16 is activated thereafter, unscrupulous persons could open and close the door at will to access coins or the inner workings of the gaming machine without the microprocessor 22 being automatically informed.
There exists a need for a door monitor for gaming machines which will continuously operate independent of the gaming machine power supply and which prevents the problem of tampering with the monitor while a gaming machine door is opened.
The present invention comprises a method and system for monitoring game machine doors which discloses when a door has been opened or when the door monitor has been tampered with.
A door-monitoring method and system according to the present invention uses a small amount of power and is capable of operating independent of a gaming machine power supply.
According to one embodiment of the present invention, a normally-closed switch is used to indicate whether a door is open or closed. Utilizing such a switch, the switch is closed when the door is closed, and thus a circuit is completed. When the door is opened, the switch is opened and the circuit is broken, triggering an electronic latch output which indicates that the door has been opened. When the door is later closed, thereby closing the switch, the electronic latch output continues to indicate that the door has been opened until its reset input is activated. In one variation of this embodiment, the electronic latch output is coupled to a game controller and the game is disabled when the door has been opened or the monitor has been tampered with.
In one embodiment of the present invention, a door-monitoring signal is provided by a battery connected to an oscillator, which is then connected via a normally-closed switch to ground. In this embodiment, the oscillator assures that power from the battery is not dissipated quickly, but rather is capable of being used to produce a signal for an extended period of time. In one variation of this embodiment, one battery may be used to produce a signal for a year or more.